as washington teeters on the edge of the fiscal cliff, there is still no deal. as talks continued overnight, a voice of frustration erupted on the senate floor. >> something has gone terribly wrong when the biggest threat to our american economy is our american congress. >> reporter: the republican and democratic senate leaders negotiated all weekend long. the talks hit a brick wall. harry reid saying he was unable to even counter the latest republican offer. >> at this stage, we're not able to make a counteroffer. it appears that there are things that stop us from moving forward. >> reporter: that prompted mitch mcconnell to call for a lifeline. >> i also placed a call to the vice president to see if he could help jump-start the negotiations on his side. i want everyone to know i'm willing to get this done. but i need a dance partner. >> reporter: and with that, vice president biden has now emerged as a key player, playing a direct role in the effort to strike a last-minute deal. the key sticking points remain the same. the white house wants taxes to go up on t